Re: [XEN][RFC PATCH 01/13] device tree: Remove __init from function type

[Julien Grall <julien@xxxxxxx>]

Hi Vikram,

Apologies for the late answer. I was away most of September and still 
catching up with my e-mails.
On 02/09/2021 07:05, Vikram Garhwal wrote:
> Change function type of following function to access during runtime:
>      1. handle_device_interrupt()
>      2. map_irq_to_domain()
>      3. map_range_to_domain()
>      4. unflatten_dt_node()
>      5. unflatten_device_tree()
I would prefer if the __init is removed as it get used.

> Remove .init from domain_build.o and move map_range_data declaration to
> domain_build.h.
Skimming through the rest of the series, I think the function you are 
trying to use will be misplaced because you are not looking to build a 
domain. Instead, you are looking to add more devices.
So I think it would be better to move the functions outside of 
domain_build.c. One possibility would be device.c.
Cheers,

> These changes are done to support the dynamic programming of a nodes where an
> overlay node will be added to fdt and unflattened node will be added to dt_host.
> Furthermore, irq and mmio mapping will be done for the added node.
>
> Signed-off-by: Vikram Garhwal <fnu.vikram@xxxxxxxxxx>
> ---
>   xen/arch/arm/Makefile              |  2 +-
>   xen/arch/arm/domain_build.c        | 15 ++++-----------
>   xen/common/device_tree.c           | 18 +++++++++---------
>   xen/include/asm-arm/domain_build.h | 10 ++++++++++
>   xen/include/xen/device_tree.h      |  5 +++++
>   5 files changed, 29 insertions(+), 21 deletions(-)
>
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index 3d3b97b..bef4517 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -15,7 +15,7 @@ obj-y += decode.o
>   obj-y += device.o
>   obj-$(CONFIG_IOREQ_SERVER) += dm.o
>   obj-y += domain.o
> -obj-y += domain_build.init.o
> +obj-y += domain_build.o
>   obj-y += domctl.o
>   obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
>   obj-y += gic.o
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 206038d..3a457d3 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -47,12 +47,6 @@ static int __init parse_dom0_mem(const char *s)
>   }
>   custom_param("dom0_mem", parse_dom0_mem);
>   
> -struct map_range_data
> -{
> -    struct domain *d;
> -    p2m_type_t p2mt;
> -};
> -
>   /* Override macros from asm/page.h to make them work with mfn_t */
>   #undef virt_to_mfn
>   #define virt_to_mfn(va) _mfn(__virt_to_mfn(va))
> @@ -1144,7 +1138,7 @@ int __init make_chosen_node(const struct kernel_info 
> *kinfo)
>       return res;
>   }
>   
> -int __init map_irq_to_domain(struct domain *d, unsigned int irq,
> +int map_irq_to_domain(struct domain *d, unsigned int irq,
>                                bool need_mapping, const char *devname)
>   {
>       int res;
> @@ -1210,7 +1204,7 @@ static int __init map_dt_irq_to_domain(const struct 
> dt_device_node *dev,
>       return 0;
>   }
>   
> -static int __init map_range_to_domain(const struct dt_device_node *dev,
> +int map_range_to_domain(const struct dt_device_node *dev,
>                                         u64 addr, u64 len,
>                                         void *data)
>   {
> @@ -1300,9 +1294,8 @@ static int __init map_device_children(struct domain *d,
>    *   < 0 error
>    *   0   success
>    */
> -static int __init handle_device_interrupts(struct domain *d,
> -                                           struct dt_device_node *dev,
> -                                           bool need_mapping)
> +int handle_device_interrupts(struct domain *d, struct dt_device_node *dev,
> +                             bool need_mapping)
>   {
>       unsigned int i, nirq;
>       int res;
> diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
> index 03d25a8..cda21be 100644
> --- a/xen/common/device_tree.c
> +++ b/xen/common/device_tree.c
> @@ -1750,12 +1750,12 @@ int dt_count_phandle_with_args(const struct 
> dt_device_node *np,
>    * @allnextpp: pointer to ->allnext from last allocated device_node
>    * @fpsize: Size of the node path up at the current depth.
>    */
> -static unsigned long __init unflatten_dt_node(const void *fdt,
> -                                              unsigned long mem,
> -                                              unsigned long *p,
> -                                              struct dt_device_node *dad,
> -                                              struct dt_device_node 
> ***allnextpp,
> -                                              unsigned long fpsize)
> +static unsigned long unflatten_dt_node(const void *fdt,
> +                                unsigned long mem,
> +                                unsigned long *p,
> +                                struct dt_device_node *dad,
> +                                struct dt_device_node ***allnextpp,
> +                                unsigned long fpsize)
>   {
>       struct dt_device_node *np;
>       struct dt_property *pp, **prev_pp = NULL;
> @@ -1986,7 +1986,7 @@ static unsigned long __init unflatten_dt_node(const void 
> *fdt,
>   }
>   
>   /**
> - * __unflatten_device_tree - create tree of device_nodes from flat blob
> + * unflatten_device_tree - create tree of device_nodes from flat blob
>    *
>    * unflattens a device-tree, creating the
>    * tree of struct device_node. It also fills the "name" and "type"
> @@ -1995,7 +1995,7 @@ static unsigned long __init unflatten_dt_node(const void 
> *fdt,
>    * @fdt: The fdt to expand
>    * @mynodes: The device_node tree created by the call
>    */
> -static void __init __unflatten_device_tree(const void *fdt,
> +void unflatten_device_tree(const void *fdt,
>                                              struct dt_device_node **mynodes)
>   {
>       unsigned long start, mem, size;
> @@ -2118,7 +2118,7 @@ dt_find_interrupt_controller(const struct dt_device_match 
> *matches)
>   
>   void __init dt_unflatten_host_device_tree(void)
>   {
> -    __unflatten_device_tree(device_tree_flattened, &dt_host);
> +    unflatten_device_tree(device_tree_flattened, &dt_host);
>       dt_alias_scan();
>   }
>   
> diff --git a/xen/include/asm-arm/domain_build.h b/xen/include/asm-arm/domain_build.h
> index 34ceddc..17449b1 100644
> --- a/xen/include/asm-arm/domain_build.h
> +++ b/xen/include/asm-arm/domain_build.h
> @@ -4,10 +4,20 @@
>   #include <xen/sched.h>
>   #include <asm/kernel.h>
>   
> +struct map_range_data
> +{
> +    struct domain *d;
> +    p2m_type_t p2mt;
> +};
> +
>   int map_irq_to_domain(struct domain *d, unsigned int irq,
>                         bool need_mapping, const char *devname);
>   int make_chosen_node(const struct kernel_info *kinfo);
>   void evtchn_allocate(struct domain *d);
> +int handle_device_interrupts(struct domain *d, struct dt_device_node *dev,
> +                             bool need_mapping);
> +int map_range_to_domain(const struct dt_device_node *dev, u64 addr, u64 len,
> +                        void *data);
>   
>   #ifndef CONFIG_ACPI
>   static inline int prepare_acpi(struct domain *d, struct kernel_info *kinfo)
> diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
> index b02696b..a4e98a7 100644
> --- a/xen/include/xen/device_tree.h
> +++ b/xen/include/xen/device_tree.h
> @@ -177,6 +177,11 @@ int device_tree_for_each_node(const void *fdt, int node,
>    */
>   void dt_unflatten_host_device_tree(void);
>   
> +/*
> + * unflatten any device tree.
> + */
> +void unflatten_device_tree(const void *fdt, struct dt_device_node **mynodes);
> +
>   /**
>    * IRQ translation callback
>    * TODO: For the moment we assume that we only have ONE
--
Julien Grall